From 37c1d3e3b618b7cdd31ba9cbf5da1324fabc5ca9 Mon Sep 17 00:00:00 2001 From: Wolfgang Bangerth Date: Tue, 21 Jan 2025 15:17:58 -0700 Subject: [PATCH] Add a changelog entry. --- .../incompatibilities/202501121Bangerth | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 doc/news/changes/incompatibilities/202501121Bangerth diff --git a/doc/news/changes/incompatibilities/202501121Bangerth b/doc/news/changes/incompatibilities/202501121Bangerth new file mode 100644 index 0000000000..f892630883 --- /dev/null +++ b/doc/news/changes/incompatibilities/202501121Bangerth @@ -0,0 +1,26 @@ +Changed: The SolverControl, ReductionControl, and +IterationNumberControl classes have constructors that take two boolean +flags `log_history` and `log_result`. The first of these represents +whether each time these classes are asked to evaluate progress of an +iterative solver, it should output information about the current +number of the iteration and the current residual to the `deallog` +object. The latter flag determines whether this kind of output should +be generated once the solver has been determined to have either +succeeded or failed, i.e., at the end of the iteration. By default, +these flags were set to `false` and `true`, respectively. + +Creating and formatting this kind of output turns out to be +surprisingly expensive. This is a nuisance because by default, the +`deallog` variable (via the constructor arguments of the LogStream +class) is instructed to simply ignore whatever information is sent to +it, rather than putting the output onto the screen or into a log file. + +As a consequence, the defaults of the constructor arguments of the +three classes mentioned above have been changed from `false` and +`true` to `false` and `false`. If you have instructed `deallog` to +pass information given to it to the screen or into an output file, you +can always explicitly also set the constructor arguments of +SolverControl, ReductionControl, or IterationNumberControl objects to +retain the previous behavior. +
+(Wolfgang Bangerth, 2025/01/21) -- 2.39.5